System for collecting and utilizing solar heat.



No. 683,088. Patented Sept. 24, l90l. K. C. WIDEEN.

. SYSTEM FOR COLLECTING AND UTILIZING SOLAR HEAT.

- (Application filed Apr. 27, 1900.) (N u M 0 d a I 2 Sheets-Sheet l.

W TNESSES:

I N V E N TO R JQM g 7% m) /fit w I y Affomeys,

Patented Sept. 24, I90l. K. C. WIDEEN. SYSTEM FOR COLLECTING AND UTILIZING SOLAR HEAT.

(Application filed Apr. 27, 1900.)

2 Sheets-Sheet 2.

(No Model.)

SSES:

. Nrrn STATES KNUT o. WIDEEN, OF NEW YORK, N. Y.

SYSTEM FOR COLLECTING AND UTILIZING SOLAR HEAT,

SPECIFICATION forming part of Letters lateznt N0. 583,088, dated September 24, 1901.

Application filed April 27, 1900. Serial No. 14,638. (No model.)

I To all whom it may concern..-

Be it known that I, KNUT C.WIDEEN, a subject of the King of Sweden and Norway, residing in the city, county, and State of New York, haveinvented certain new and useful Improvements in Systems for Collecting and UtilizingSolar Heat, of which the following is a specification.

My invention provides an economical system for collecting the heat radiated by the sun over a large surface and concentrating the same in a furnace.

It provides also for the utilization of such concentrated heat for the convenient melting of refractory ores, metals, &c.

It provides also various other improvements,all of which will be set forth in detail in the following specification.-

In the accompanying drawings, illustrating one embodiment of my invention, Figure 1 is a vertical section of my complete system omitting most of the details, such as the sup ports of the various parts. showing the relative positions of the furnace and the mirrors. Fig. 3 is a section of one of my mirrors complete. Fig. 4 is a plan of one of my individual mirrors in its frame ready for use. Figs. 5 and 6 are a vertical section and plan, respectively, of my furnace; and Fig. 7 is a perspective of the adjustable support for my individual mirrors.

The principal elements'of my system are a large concave primary reflector or spherical or approximately spherical mirror formed of a number of relatively small individual mirrors AA, which I term sectional mirrors, a furnace B, preferably located in the center of said large mirror, and a secondary mirror or reflector 0, located opposite said group of mirrors A A and said furnaceB and serving to receive the suns rays as reflected from said primary reflector and to again reflect said rays and converge them to a focus within the furnace. For most convenient operation the primary concave reflector is located at or near the floor-surface of the plant, with itsconcavity upward, and'the secondary reflector is located above said primary reflector and is Fig. 2 is a plan 'm'ary reflector and also constantly focuses 'saidrays at the same point in the furnace.

I prefer to arrange the primary reflector with its axis approximately vertical, so that it occupies a substantially horizontal position and can be constructed of much greater size than if it stood in a vertical position.

In the construction shown the reflector C is made convex, whereby a smaller reflector may be used than if it were plane, thus reducing interference with the direct rays of the sun in their passage tothe concave or primary reflector and being considerably cheaper for the same amount of heat collected. The reflectorC is suspended from a trolley or other support c,which travels back and forth on the horizontally-curved rail 0. The movement ofthe trolley c is regulated by a clock mechanism 0 which is connected to adriving-wheel c of said trolley. Said clock mechanism is regulated so as to move at the uniform rate at which the sun moves and to propel the trolley in the direction is conveniently effected by supporting the reflector loosely from a pair of racks cflwhich gear'with a pinion on the driving-wheel of. the trolley or which are connected in some other way with the clockwork. The details of these connections as well as the propelling mechanism are not material to my invention, and they are therefore not shown in detail. The track or rail 0' may be supported in any convenient way, preferably by means of slender uprights-and guy-wires, so as to avoid. as far as possible obstructing the admission of the heat-rays to the concave mirror.

Fig. 2 shows one arrangement of. the sectional mirrors A A which attains consider-' able compactness thereof. The furnace B is surrounded by an open space sufiicient to admit the passage of the operator, and the mirrors are made in two sizes and are placed as close to each other "as possible. Preferably,

.also,they are raised above the floor a suflicient considerably, varied and is shown only as one mode of arranging the parts. The track 0 is shown at approximately the position it would have in the northern part of this country and with the central radius of the large concave mirror standing in the vertical position. Each of the sectional mirrors A A, however, is adjustable in elevation and inclination,so that by lowering those on one side and raising those on the other side of the furnace the central axis may be changed from the vertical to an inclined position to meet the corresponding changes in the inclination of the sun due to the variation of the seasons, or by changing equally all' those at equal distances from the center (using for a perfectly accurate result sectional mirrors of the desired degree of curvature, as hereinafter more fully explained) the degree of curvature may be regulated to correspond with the distance to the secondary reflector 0 without altering the position of the axis of the reflected rays. As a means of adjusting the position of the sectional mirrors I show a support A from which said mirror depends, and an adjustable connection a for raising or lowering said mirror. It will be understood that there are four supports A for each mirror. The primary reflector having its small segments A and A arranged and inclined as shown in Fig. 1 and the secondary reflector 0 being also arranged as in Fig. 1, the suns rays S at all points of the primary reflector are reflected upward, as shown atS, to the secondary reflector C, where they are again reflected, as shown at 5*, and focused at F in the furnace. It is apparent that by the use of a large primary reflector or, what ,is equivalent, by. the use of a large number of sectional reflectors A A, set in sucha relative position as to give practically one large primary reflector, I can accumulate at the point F so large a number of heat-rays as to intensify many times the heat of the sun in its ordinary diffused condition. I have, in fact, obtained with experimental systems a sufflciently high temperature to fuse the most refractoryores and, pure metals.

It is apparent that some of the advantages of my system might be obtained with the use of a group of plane reflectors adjustable relatively to each other so as to obtain a nearlyspberical large reflector or that they might be obtained by'the use of a great number of small spherical sectional reflectors; yet .it is obviously advantageous to usecurved mirrors of considerable size. Such a mirror is shown in Figs. 3, 4, and 7.

D is a casting having a body portion circular in outline and depressed at the center, so as to form a segment of a sphere, and having a rim (1 projecting upward all around such center portion, forming a chamber E.

On the outside of the rim are formed a series of perforated lugs d used in attaching the mirror to its supports or in handling the casting in 'the process of manufacturing the mirror.

G is the plate, of reflecting material-such as silvered glass,celluloid, or polished metalwhich forms the reflector proper.

E is a backing, of stearin, rosin, lead, or thelike, which is filled into the chamber D by a process set forth in my application for patent for improvements in curved mirrors and apparatus and process for making the same, filed June 12, 1900, Serial No. 20,087. The stearin or the'like isquite hard, gives a firm backing to the mirror, and stifiens it in its curved shape. Stearin is especially useful, because of its slight expansion under heat and also its slight contraction in solidifying and because it melts at a comparatively low temperature (77 centigrade) and is about as hard as wood when cold.

The curvature of my individual sectional reflectors is of approximately the same degree as that of the complete reflector. Where the degree of curvature of the complete reflector is adjusted through any considerable range, that of the individual reflectors is changed to correspond therewith by varying the quantity of backin g material in the chamber. Where a normally solid backing material, such as stearin, has been used, it will of course require to be softened before being diminished or increased in volume. With normally liquid or semiliquid materials, however, no preliminary softening is necessary.

For example, by using air, water, or oil as the backing material and inserting plungers through the casting, which plungers may be moved into or out of the body of the backing material, I can-vary the volume of the material sufliciently to accomplish all the necessary variations in the degree of curvature of the reflector.

For the utilization of the high degree of heat generated in my system a special construction of furnace is advisable. Figs. 5 and 6 show a furnace especially adapted for use in my system, which is designed to give the maximum of strength with the minimum interference with the heat-rays and a most convenient means of introducing the material to be fused. The furnace proper consists of a cylinder M, preferably of sheet metal, having a base m of the same material and a manhole m atone side thereof, the cover of which opens inward, so that the pressure within will assist in securing a tight closure for said manhole.

F shows the focus of the rays S S as they come from the secondary reflector C.

N shows a pot or crucible, preferably of highly refractory material, for receiving-the ore or metal.

0 is a pipe or tube for conveying the ores, metals, or mixed materials which are to be passed through the focus F. Preferably the upper end of said pipe is curved, as shown I at 0, and bent downward, and the material is introduced in a powdered condition, the mouth of the pipe being so placed as to direct the charge through the focus and into the pot N. The tube 0 maybe made adjustable to correspond with variations in the position of the focus or for other purposes.

To avoidvolatilization, with some ores it is necessary to work at very high pressures,

while with other materials to avoid absorption of air it is necessary to work in a vacuum or in other gases than are in the atmosaround the wall M near the top thereof. The

. r bracing the outer webs 7' grill R, as shown most clearly in-Fig. 6, is preferably composed of a casting having an outer ring '1' and a series of thin deep radial webs 0', meeting at the center, a second series of webs 1' connecting the adjacent webs 'r" and a-third series of approximately radial webs This grill will of necessity be highly heatedin the use of my furnace, and in order to avoid too great expansion and distortion of the same I provide for the passage of a cooling fluid, either a liquid or gas, through the spaces between the webs thereof and between the adjacent sheets of glassor the like. The cooling fluid passes into said grill through an opening 1' in the outer ring '1, the furnace-wall M being perforated at a corresponding point-to permit the introduction of the fluid, and thence through perforations r in the interior webs successively through all of the compartments in the grill, as shown by the arrows, and finally out through the passage 4". Fig. 6 shows diagrammatically a cooler T, through which the cooling fluid is passed from the passage '1" back again to the passage r and which maintains a continuous current through the grill, absorbing and carrying away the heat thereof very rapidly. The web members 7, W, and r are made as thin as possible, "r and r being preferably of sheetsteel. The thickness of these parts is somewhat exaggerated in the drawings over what it would be in' practice.

. holding the cover down against great presfaces and to permit the'cooling fluid to ;rap-.

For the purpose of idly -carry away its heat. Connected with the cooler T is also a compressor, both the cooler and compressor being of any preferred type, and therefore not illustrated in detail. By compressing the fluid between the inner sheet and that next to it to a pressure less than that in the furnace I obtain a net pressure on the inner sheet P equal to the difference between the furnace-pressure and that in the fluid. By compressing the fluid in the second space to a less pressure than that in the first space I obtain a similar net pressure on the second sheet. I am thus enabled to use any desired pressure in the furnace with only a fair working pressure on the individual sheets P by reducing the pressure in the spaces step by step until a pressure is obtained which only exceeds that of the 'atmosphere by the safe working resistance of the plate. The total pressure is of course transmitted through the successive grills to the angle-iron Q.

Though I have described with great par ticularity of .detail one system embodying my invention, yet it will be apparent that many modifications of the same both in the general arrangement and in the individual elements thereof are possible without sacrificing all the advantages of my invention and without departing from the principle thereof.

What I claim, therefore, and desire to secure'by Letters Patent, are the following-defined combinations and elements, all substantially as described:

v 1. The combination of a normally stationary primary reflector for receiving the rays from the sun and-converging them, a secondary reflector for receiving said converged rays and focusing them, and means for moving said secondary reflector to correspond with the hourly variation of the sun.

2. The combination of a normally stationary primary reflector having a substantially vertical axis for receiving the-rays from the sun and converging them, a secondary reflector for receiving said converged rays andfocusing them, and means for moving said sec 'ondary reflector to correspond with the hourly variation of the sun. 3. The combination of a normally stationary primary reflector for receiving the rays from the sun and converging them, a secondary reflector for receiving said converged rays and focusing them, and means for moving sun and moving it angularly to maintain its central axis in fixed relation with the axis of the converged rays.

5. The combination of a normally stationary primary reflector for receiving the rays of the sun and converging them, a secondary reflector for receiving said converged rays and focusing them, and a clockwork for moving said secondary reflector to correspond with the hourly variation of the sun.

6. The combination of a normally stationary primary reflector for receiving the rays of the sun and converging them, a convex secondary reflector for receiving said converged rays and focusing them, and means for moving said secondary reflector to correspond with the hourly variation of the sun.

7. The combination of a normally stationary primary reflector for receiving the rays from the sun and converging them, and a secondary reflector for receiving said converged rays and focusing them, said primary reflector being adjustable to correspond with the daily variation of the sun, and said secondary reflector being, movable to correspond with the hourly variation of the sun.

8. The combination of a normally stationary primary reflector for receiving the rays from the sun and converging them, a secondary reflector for receiving said converged rays and focusing them, means for moving saidsecondary reflector to correspond with the hourly variation of the sun, and a furnace in which said rays are focused.

9. The combination of a normally station ary primary reflector for receiving the rays from the sun and converging them, a secondary reflector for receiving said converged rays and focusing them, a furnace, and means for moving said secondary reflector to maintain the focus of said rays within said furnaceduring the variation of the sun.

1 0. Acomplete spherically-curved reflector comprising a number of sectional reflectors each of whichis spherically curved.

11. A complete spherically-curved reflector comprising a number of sectional reflectors each of which is spherically curved and of the same degree of curvature as the complete reflector. V

12. Acompletespherically-curved reflector comprising a number of sectional reflectors each of which is spherically curved, said sectional reflectors being bodily vadjustable independently of each other.

13. A complete spherically-curved reflector comprising a number of sectional reflectors each of which is spherically curved, means for varying the degree of curvature of said complete reflector, and means for correspondingly varying'the degree of curvature of each of said sectional reflectors.

14. A cover for a solar furnace comprising a series of transparent plates and a grill between each adjacent pair of said plates.

' 15. The combination with a cover for a solar furnace comprising a series of transpare'saoss ent plates and a grill between each adjacent pair of said plates, of means for circulating a cooling fluid between said plates.

16. The combination with a cover for a so lar furnace comprising a series of transparent plates and a grill between each adjacent pair of plates, of means for circulating a cooling fluid under pressure between said plates.

17. The combination with a cover for a highpressure furnace,com prising a series of plates; of means for introducing an outward pressure between each adjacent pair of plates.

18. The combination with a cover fora highpressure furnace comprisinga series of plates, of means for introducing a body of fluid under pressure between each adjacent pair of plates.

' 19. The combination with a cover for a highpressure furnace comprising a series of plates and means for maintaining said plates separate from each other, of means for introducing an outward pressure between each adja cent pair of plates.

20. The combination witha cover fora highpressure furnace comprising a series of plates,

' and means for maintaining said plates separate from each other, of means for introducing a body of fluid under pressure between eachadjacent pair of plates.

21. The combination witha cover for ahighpressure f urnace comprising a series of plates, and a grill between each adjacent pair of plates for maintaining said plates separate from each other, of means for introducing an outward pressure between each adjacen pair of plates.

22.. The combination with a cover for a highpressure furnace comprising a series of plates, of means for introducing an outward pressure between each adjacent pair of plates, the pressures between successive pairs being reduced outwardly.

23. The combination witha coverforahighpressure furnace comprising apair of plates, of'mean's for introducing an outward pressure between said plates, said pressure being less than, the pressure in said furnace.

24. The combination with a primary reflector for receiving the rays from the sun and converging them, and a secondary reflector for receiving said converged rays and focusiug them,of a solar furnace havinga cover comprising aseries of transparent plates and a grill between each adjacent pair of plates, said rays being passed through said cover and focused within said furnace,

25. The combination with a primary reflector for receiving the rays from the sun and converging them, and a secondary reflector for receiving said converged rays and fo- -cusiug them, of a solar furnace having a;cover comprising a series of transparent plates, and means for circulating a cooling fluid between said plates, said rays being passed through said cover and focused within said furnace.

26. The combination of a normally sta tionary primary reflector for receiving the converged rays and angularly so as to con-.

stantly focus said rays within said furnace.-

27. The combination of a normally stationary primary-reflector having a substantially vertical axis, for receiving the rays from the sun and converging them, a secondary reflector arranged above said primary reflector, for receiving said converged rays and focusing them, a furnace, and means for moving said secondary reflector bodily so as to 15' constantly receive said converged rays and angnlarly so as to constantly focus said rays within said furnace.

In witness whereof I have hereunto signed my name in the presence of two subscribing 20 witnesses.

, KNUT o. WIDEEN. Witnesses:

THOMAS F. WALLACE, Q FRED WHITE. 

